1. Field of the Invention
The present invention generally relates to an apparatus and method for controlling hydrogen purging and, more particularly, to an apparatus and method for controlling hydrogen purging, which varies a hydrogen purging period based on a driving style of a driver.
2. Description of the Related Art
A fuel cell vehicle includes a fuel cell stack in which a plurality of fuel cells used as a power source are stacked, a fuel supply system configured to supply hydrogen or the like, which is a fuel, to the fuel cell stack, an air supply system configured to supply oxygen, which is an oxidant required for electrochemical reactions, a water/heat management system configured to adjust the temperature of the fuel cell stack, etc. The fuel supply system is configured to decompress compressed hydrogen in a hydrogen tank, and supply the decompressed hydrogen to the fuel electrode (anode) of the stack, and the air supply system is configured to supply external air, suctioned by operating an air blower, to the air electrode (cathode) of the stack.
When hydrogen is supplied to the anode of the stack and oxygen is supplied to the cathode, hydrogen ions are separated at the anode via a catalytic reaction. The separated hydrogen ions are transferred to an oxidation electrode, which is the cathode, through a membrane. The hydrogen ions separated at the anode, and electrons and oxygen together cause an electrochemical reaction at the oxidation electrode, and thus electrical energy can be obtained through such a reaction. In particular, an electrochemical oxidation of hydrogen occurs at the anode, and an electrochemical reduction of oxygen occurs at the cathode. Due to the movement of electrons generated in this procedure, electricity and heat are generated, and vapor or water is generated due to a chemical action in which hydrogen and oxygen combine. Further, nitrogen that occupies the largest part of atmospheric air may be transferred to the anode through the membrane due to diffusion on the cathode. Such nitrogen acts as an impurity on a hydrogen electrode. Hydrogen purging is performed to remove nitrogen, that is, the impurity. Hydrogen purging is required to remove such impurities, but hydrogen purging wastes hydrogen to be used as fuel, and thus the hydrogen utilization rate decreases, thus deteriorating driving efficiency.